cities = {
    ("Vancouver", [49.2827, -123.1207]): 631_486,
    ("Denver", [39.7392, -104.9903]): 716_492,
    ("Oslo", [59.9139, 10.7522]): 693_491,
    ("Berlin", [52.5200, 13.4050]): 3_769_495,
    ("Vienna", [48.2082, 16.3738]): 1_900_000,
    ("Warsaw", [52.2297, 21.0122]): 1_791_000,
    ("Belgrade", [44.7866, 20.4489]): 1_395_000,
}
